[TowerTalk] Fwd: antennas in fresh water

hanslg at aol.com hanslg at aol.com
Sat Nov 14 20:24:24 PST 2009

I believe with a dielectric constant around 80 the water surface will 
act as a good reflector especially as the graze angle is small. This is 
the same way as glass can reflect light and is regardless how good the 
water is conducting.

The water surface will act as a very good reflector up to the moment 
any waves are large enough to be of similar size as the wavelength.

73 de

Hans N2JFS

Rob's comments would suggest that at the bottom of the lake, where the 
is in contact with the earth, the conductivity would be good, just like 
earth with an insulator above it - so while the WATER is not doing the
radials' job, the bottom of the lake IS.

       Rex Lint
       Merrimack, NH
-----Original Message-----
From: towertalk-bounces at contesting.com
[mailto:towertalk-bounces at contesting.com] On Behalf Of Roger Parsons
Sent: Friday, November 13, 2009 5:10 PM
To: towertalk at contesting.com
Subject: [TowerTalk] antennas in fresh water

Thanks for your comments Rob - I generally agree with your 

However, my particular cases were (1) An AV3 10-15-20m vertical which 
much better at ground level close to the lake than it did 40' from the 
with the base at 20' with tuned radials and (2) A 40m vertical which 
dramatically better about 10' from the lake than it did sitting in a 
area 300' from the lake.

On 160m I use a 95' top loaded vertical about 400' from the lake with 
of long ground radials - it seems to work quite nicely. I recently put 
up a
60' inverted L close to the lake (mostly because I could :-) - I am 
forward to comparing the two. On receive there seems to be little 
and I suspect that will be the case on transmit as well when I get 
round to
making the switch box.

I still think that the clear take-off over the lake must help - possibly
because it is not obstructed but also possibly because it is likely to 
be a
better reflector of grazing signals.

73 Roger


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